1. Field of the Invention
This invention relates to an electrode for use in measuring ion concentration. More specifically, this invention relates to a solid electrode for use in measuring unknown ion concentrations in solution.
2. Description of the Prior Art
A review of the ion-selective electrode art is set forth in Buck, Analytical Chemistry, 46(5): 28R (1974); Koryta, Analytica Chimica Acta, 61:329 (1972); and Koryta, Analytica Chimica Acta, 91:1 (1977), said publications and the citations therein being incorporated herein in toto by reference.
In particular, U.S. Pat. No. 3,856,649 discloses a solid state electrode comprising an electrically conductive inner element with a salt disposed on a surface portion thereof. The cation moeity of the salt is a cation form of the conductive inner element. A hydrophilic layer is in intimate contact with the salt. The hydrophilic layer includes a water soluble salt of the anion moeity of the salt. A hydrophobic layer is in intimate contact with the hydrophilic layer.
A very serious problem encountered in using an electrode manufactured according to the teachings of U.S. Pat. No. 3,856,649 is their generally short operable life span.